Hexagram 16
Yu (Enthusiasm) - Music and Joy
豫
Meaning and Overview
The upper trigram of the Yu hexagram is Zhen, representing thunder and movement. The lower trigram is Kun, representing earth and soil. The inner trigram, formed by lines 2, 3, and 4, is Gen, representing stone, which is a percussion instrument. Therefore, the Yu hexagram is the hexagram of musical performance. The Great Image says: 'The ancient kings, through music, honored virtue, and presented it abundantly to the Supreme God, matching it with the ancestors.' From this, we know that in ancient times, when sacrificing to God and ancestors, music was always performed. The ancient ritual and music system had strict regulations: the king's instruments were arranged on four sides, called 'gong xian'; the feudal lord's instruments on three sides, called 'xuan xian'; the minister's instruments on two sides, called 'pan xian'; the scholar's instruments on one side, called 'te xian'. Common people had no prescribed use of music. From the first line of the Yu hexagram, 'Crying out in enthusiasm: misfortune,' using musical instruments for joy was dangerous; in ancient times, common people were not allowed to display instruments or exceed ritual regulations in using music. The second line, being central and correct, indicates that using music conforms to ritual regulations. The fourth line is the main line of the Yu hexagram, hence it says, 'From enthusiasm, great gain.' The Commentary says: 'The firm responds and the will acts; following and moving, this is Yu.' The Qian hexagram is closely related to ritual, while the Yu hexagram is closely related to music. The two hexagrams, Qian and Yu, are connected, and ritual and music depend on each other, which is also reflected in the Book of Changes. In the Commentary on the Appended Phrases, the original meaning of the Yu hexagram is 'to set up multiple gates and beat the watchman's clapper, to await violent guests,' using a wooden stick to sound the alarm, reminding people to be safe at night; the sound of the wooden stick travels far.
Chinese Interpretation
《豫》卦上卦为震，为雷，为动。下卦为坤，为地，为土。《豫》卦中间互卦，即二、三、四爻组成《艮》卦，艮为石，石为，是打击乐器，因此说，《豫》卦是音乐演奏之卦。大象辞说：“先王以作乐崇德，殷荐之上帝，以配祖考。”由此可知，上古祭祀上帝和祖先时，都要演奏音乐。古代的礼乐制度有严格规定，王的乐器是四面陈列，称作宫县。诸侯乐器三面陈列，称作轩县。卿大夫乐器二面陈列，称作判县。士的乐器一面陈列，称作特县。一般庶民，没有规定用乐。由《豫》卦初六爻辞来看，“鸣豫，凶”，用乐器作乐，凶险，上古是不准庶民陈列乐器，不准庶民越礼制用乐的。六二爻是中正之爻，表示用乐合乎礼制规定。九四爻是《豫》卦主爻，因此说“由豫，大有得”，《传》说：“刚应而志行，顺以动，豫。”《谦》卦与礼制密切相关，《豫》卦与乐制密切相关，《谦》与《豫》两卦相连，礼乐相须，《周易》里面也有反映。在《系辞传》里面，《豫》卦的原意是“重门击柝，以待暴客”，用木头棒子打更报警，提醒人们晚上注意安全，木棒敲击的声音传得很远。
Line Interpretations
These passages include the core hexagram statement, the six moving line texts, and traditional commentary where available. Read them as layered guidance: the early lines describe the root of the situation, while later lines reveal development, pressure, and outcome.
利建侯行师。
有利于封建诸侯，兴师动众。
It is favorable to enfeoff feudal lords and mobilize armies.
It is beneficial to establish feudal lords and raise armies.
初六，鸣豫，凶。
初六爻，自鸣得意，凶险。
First six: Crying out in enthusiasm — misfortune.
The first line: Self-satisfied enthusiasm — danger.
六二，介于石，不终日，贞吉。
六二爻，知道事物变化之机，就如作为分界线的石碑一样，清楚明白，见机而作，立刻择善而从，坚守正道，吉祥。
Six in the second: Firm as a rock, not lasting a whole day — perseverance brings good fortune.
The second line: Knowing the moment of change, like a boundary stone, clear and distinct, acting on the opportunity, immediately choosing the good and following it, steadfast in correctness — good fortune.
六三，盱豫悔，迟有悔。
六三爻，谄媚求欢，导致后悔；迟疑不决，又生后悔。
Six in the third: Looking up in enthusiasm — regret; hesitation brings regret.
The third line: Flattering to seek pleasure leads to regret; indecision also brings regret.
九四，由豫，大有得。勿疑，朋盍簪。
九四爻，众人依靠他而获得快乐，大有收获。不必疑虑，朋友像簪子聚合一样会聚拢来。
Nine in the fourth: From enthusiasm, great gain. Do not doubt — friends gather like hairpins.
The fourth line: People rely on him to obtain joy — great gain. Do not doubt; friends will gather like hairpins.
六五，贞疾，恒不死。
六五爻，坚守正道，虽患病，但长久不会死亡。
Six in the fifth: Perseverance in illness — enduring, not dying.
The fifth line: Persevering in correctness, though ill, will not die for a long time.
上六，冥豫，成有渝，无咎。
上六爻，昏冥纵乐，最终有所改变，没有灾祸。
Top six: Dark enthusiasm — completion brings change, no blame.
The top line: Dark indulgence in pleasure — ultimately there is change, no misfortune.